Fabricating custom-fit dental prosthetics, such as restoratives, tooth replacements, inlays, onlays, veneers, full and partial crowns, bridges, implants, posts, and the like has been practiced for some time. Materials used to make the prostheses include, for example, gold, ceramics, amalgam, porcelain, and composites. A conventional process for making certain dental prosthetics involves taking an impression of a dentition using an elastomeric material from which a cast model is made to replicate the dentition. The prosthetic is then produced from the model using metal, ceramic or a composite material, followed by making modifications for proper fit and comfort. More recently, working time has been greatly reduced using digital dentistry wherein computer automation is combined with optics, digitizing equipment, CAD/CAM and milling tools. Fabrication of a dental prosthetic or other types of prostheses using these methods requires a mill blank, a solid block of material from which the prosthetic is cut or carved. Ceramic materials have typically been used as the mill block. Certain composite materials comprising a polymeric resin and a filler have also been used for this purpose, for example, MZ100 mill blocks available from 3M ESPE.